4-bit
About the 4-bit PCB
4-bit is an open source PCB design by macmade, published on GitHub under the CERN-OHL-1.2 license. It is a 4-layer board measuring 225.6 × 187.5 mm, with 293 components from 22 distinct parts.
By type, the board carries 166 resistors, 93 transistors, 16 LEDs, 9 switches, 4 capacitors and 2 diodes.
From the project
4-Bit Computer
This learning project consists of a 4-bit adder, using NPN transistors. Inspiration comes from www.waitingforfriday.com.
The goal is to create a complete project using KiCad: schematics and PCB. Components will be ordered from Mouser; PCB will be ordered from OSH Park.
Schemas and PCB layouts are created with KiCad: http://www.kicad-pcb.org
This project requires the XS-Labs KiCad Library to be installed in KiCad.
4-bit bill of materials (BOM)
293 components, 22 distinct parts.
| Qty | Part | Footprint | Refs |
|---|---|---|---|
| 93 | BC547 | Transistor-Fairchild-BC546-BC547-BC548-BC549-BC550 | Q1, Q2, Q3, Q4, Q5, Q6, Q7, Q8 +85 |
| 1 | +12v | Power-Adafruit-DC-Barrel-Jack | J1 |
| 1 | +9v | Power-Keystone-9v-Battery-Holder | BT1 |
| 9 | SPDT | Switch-NKK-Series-M-SPDT | SW1, SW2, SW3, SW4, SW5, SW6, SW7, SW8 +1 |
| 1 | LM7805 | Power-Failrchild-LM78XX-TO-220 | VR1 |
| 1 | Adapter | LED-T1-3-4-5mm | DS1 |
| 1 | Battery | LED-T1-3-4-5mm | DS2 |
| 1 | Standby | LED-T1-3-4-5mm | DS3 |
| 3 | 1 | LED-T1-3-4-5mm | DS4, DS8, DS12 |
| 3 | 2 | LED-T1-3-4-5mm | DS5, DS9, DS13 |
| 3 | 4 | LED-T1-3-4-5mm | DS6, DS10, DS14 |
| 3 | 8 | LED-T1-3-4-5mm | DS7, DS11, DS15 |
| 1 | 16 | LED-T1-3-4-5mm | DS16 |
| 2 | 1N4001 | Diode-DO-41 | D1, D2 |
| 1 | 100uf | Capacitor-Vishay-515D-8mm | C1 |
| 1 | 0.33uf | Capacitor-Murata-RCE-Series-5mm | C2 |
| 1 | 0.1uf | Capacitor-Murata-RCE-Series-5mm | C3 |
| 1 | 10uf | Capacitor-Vishay-515D-5mm | C4 |
| 15 | 390 | Resistor-Ohmite-OD-Series | R1, R2, R4, R5, R6, R7, R8, R9 +7 |
| 1 | 100k | Resistor-Ohmite-OD-Series | R3 |
Show 2 more
| Qty | Part | Footprint | Refs |
|---|---|---|---|
| 101 | 10k | Resistor-Ohmite-OD-Series | R12, R13, R14, R15, R16, R17, R18, R19 +93 |
| 49 | 1k | Resistor-Ohmite-OD-Series | R25, R26, R27, R28, R29, R39, R40, R45 +41 |
4-bit design files
The KiCad project lives in the macmade/4-bit repository on GitHub; these links point at the commit this page was built from.
4-bit: common questions
How big is the 4-bit PCB?
The 4-bit measures 225.6 × 187.5 mm, has 4 copper layers and is 1.6 mm thick.
How many components are on the 4-bit?
293 components, from 22 distinct parts. The full bill of materials is listed on this page.
Where can I download the 4-bit design files?
From the macmade/4-bit repository on GitHub, which has the KiCad layout; the links under Design files point to each one.
Can I use the 4-bit design in my own project?
Yes, under the terms of its CERN-OHL-1.2 license, which macmade chose for the repository.